Difference between comets and asteroids

From raju

Q. What is the difference between a comet and an Asteroid?
A. Both asteroids and comets were formed early in the history of the solar system - about 4.5 billion years ago.

Asteroids Comets
Made up of metals and rocky material Made up of ice, dust and rocky material
Asteroids formed much closer to the Sun, where it was too warm for ice to remain solid. Comets formed farther from the Sun where ice wouldn't melt.
Comets which approach the Sun lose material with each orbit because some of their ice melts and vaporizes to form a tail.

Asteroid Belt:- The belt can be seen between Mars and Jupiter. Asteroid belts are mainly circular.

Kuiper Belt:- Many comets originate from this area. Most of these comets orbit the Sun in less than 200 years and return again in predictable intervals.

Ref:- http://www.wsj.com/articles/rosetta-mission-data-support-view-asteroids-brought-water-to-earth-1418238237